If you have a car you should do some of the dives out west. Playa Kalki/Alice in Wonderland was about the best we dove but it's out at Kura Hulanda in West Punt (45min. drive from town)
We dove Habitat Curacao's house reef at night but I just read the dive dock itself was destroyed last year. The diveshop closes around 5 so I'd recommend an afternoon dive to familiarize yourself with the reef first. The divetank/locker area is open all night and well lit. We were there in 07. there was a big octopus hunting just off the "beach" at night. For reference you'd have the lights of the resort on top of the hill to guide you back in.
My friends dove Playa Lagun the first night we were there. They had no difficulty finding the beach. It's in a cove but there's houses on the hills surrounding it. Discover Dive is at the turn-off but they close early so bring tanks.
Another good day dive for us was Varsenbaai. In one dive we saw seahorses, a big pontoon boat/barge wreck in 80' and turtles eating in 6' of water coming back in. The next dive there were 200 squid 50' off the dock.
A friend's wife is a native. She took us to a local place that might've been called Surf&Turf - it's on the water right next to the Dive Bus hut. Really casual setting and slow service but we had huge fresh lobster for not a lot of money. I might've seen someone from the kitchen getting the lobster from a pen by the water but I'm not sure.
The Ribs Factory - Oude Caracasbaaiweg 54, Willemstad had really good food and service.
Hooks Hut in Piscadera Bay is worth a stop. It's a popular beach bar and restaurant with diving on-site. If you want to eat at one of the tables in the sand you'll need to reserve in advance. Even if you're already sitting there, you'll be asked to move if there's a prior reservation.
Curacao Travel- Caribbean, Netherlands Antilles- Curacao, Dutch Caribbean if you haven't seen it already...